The present invention relates to a television receiver provided with a liquid crystal panel as a video display device.
A portable television receiver with a liquid crystal panel comprises an antenna, receiving circuit block, and liquid crystal panel driving circuit block. In the television receiver, sound and picture carrier waves pass through an antenna, inducing currents. The carrier currents are converted to intermediate-frequencies and amplified by intermediate-frequency amplifiers. The intermediate-frequency signals are detected to provide an audio signal and a video signal. The video signal is fed to the liquid crystal panel driving circuit block for display of a video image. The liquid crystal panel driving circuit composes liquid crystal driving waveforms from the video signal for driving the liquid crystal panel to develop half-tone images.
The receiving circuit block comprises a printed board or ceramic board on which various independent elements or components, including an electronic tuner in a metallic shielding case, and integrated circuits for intermediate-frequency, video signals and audio signals are mounted. The liquid crystal panel driving circuit block is constructed in a similar manner to the receiving circuit block. Namely, an integrated circuit for a liquid crystal panel driving circuit, a liquid crystal panel, and other independent components such as transistors, diodes and capacitors are mounted on a printed-wiring board.
There are many demands on a miniaturized portable liquid crystal television receiver having a small power consumption, small thickness, and high performance. However, there are many difficulties in achieving such improvements. For example, if each component is reduced in size, performance characteristics thereof will be degraded or cost will increase. It is also difficult to mount components on a printed-wiring board at high density by an automatic assembling machine. Further, if wirings are formed on a printed-wiring board at high density, electromagnetic and electrostatic inductions occur in the board, thereby reducing electrical performance of the printed-wiring board.